Flight into Darkness is the conclusion to Alchymist's Legacy, a prequel/sequel to Sarah Ash's Tears of Artamon Trilogy. The first book of Alchymist's Legacy is Tracing the Shadow (Alchymist's Legacy). "Flight into Darkness" is the second and concluding book. I strongly recommend that if you read Alchymist's Legacy , you read the Tears trilogy as well to get the full story. This will also help events in Alchymist's Legacy make more sense.
Tracing the Shadow related the back-story for the enigmatic Francian antagonists of the Tears trilogy, Celestine de Joyeuse and her partner Jagu de Rustephan, while introducing Rieuk Mordiern, Kaspar Linnaius forgotten apprentice. Celestine, Jagu and Rieuk's fates were forever altered by the appearance of the same aethyrial spirit named Azilis. Now in Flight into Darkness, the truth behind the nature of Azilis becomes known, revealing a bond that ties Celestine to the crumbling barriers between the living and the dead, and the daemon prince Nagazdiel himself.
The problem I encountered while reading this otherwise welcome expansion of the Tears universe is Part Two, which is basically an extremely abbreviated version of the Tears of Artamon itself. Not enough information is given for newcomers to actually understand all that happened in Tears, yet fans will likely find this section a bit redundant in places. Once one nears the ending chapters of part two, however, the story once again picks up, vibrant and worth every page.
Ash has a talent for linking all her novels together in a glistening thread of meaning, and in Alchemyst's Legacy she manages to bring together her Tears of Artamon trilogy and her novel Songspinners (Alchymist's Legacy brings back Girim nel Ghislain and Captain Korentan, here Lieutenant Korentan, who both have starring rolls in Ash's "Songspinners") while navigating a new story arc. Blending the Enhirre Azilis,the Francian Saint Azilia and the Allegondan Elesstar is a rather poignant way of saying that all religions share common threads, that all hold different names for the same things...while at the same time implying that none of them are entirely correct in their interpretation. Her novels are entertaining, laden with beautiful images and thought-provoking.